[Acceleration] Whitestar

[[BL]Phalanx]

Whitestar acceleration can be gauged by the scene from "Messages from Earth", where she flew from Ganymede to Jupiter in 38 seconds.

d = (a * t^2 ) / 2

d = 1.07 million km, or 1.07E9 meters
t = 38 seconds.

1.07E9 = (a * (38^2)) / 2
2.14E9 = a * 1444
a = 1.48E6 meters/sec/sec

Or roughly 151,000 g's.

[Darth Wong]

In future, you should try to explain how you get these figures, rather than simply mentioning an episode name. For example, how did you get the 38-second figure? Screen timing, dialogue, both? Were there any scene-breaks?

[[BL]Phalanx]

In "Messages from Earth", the Whitestar is sortied to destroy a Shadow Battlecrab on the surface of Ganymede. Unfortunately, the Battlecrab is activated before they can destroy it. The Shadow vessel breaks free of the base where it was being held and destroys it, then goes into orbit.

The Whitestar and the Battlecrab engage each other, then the Whitestar breaks off combat and runs, since they can't defeat the Battlecrab in a straight fight.

Sheridan comes up with the idea to try to lure the Battlecrab into Jupiter, and hope that the pressure can crush it.

The distance from Ganymede to Jupiter is given as 1,070,000 kilometers at this site:

http://seds.lpl.arizona.edu/nineplanets ... ymede.html

The 38 second figure is derived from timing the scene from the moment the Whitestar breaks combat against the Battlecrab to the moment they plunge into Jupiter.

There are cuts within the scene, but no cuts to any other scene. We saw the Battlecrab fire upon the Whitestar several times, and we are told that a single hit would destroy them. The Battlecrab was also faster than the Whitestar... it was gaining on her.

It's possible that more time passed "in-universe" than 38 seconds, but unlikely that the chase lasted very long, because the Battlecrab was firing on them the entire time and only a single hit was needed.

[Darth Wong]

There are cuts within the scene, but no cuts to any other scene.

You could say the same thing about any starship landing on any planet in every sci-fi series, yet it is always understood that some time passes between cuts.

It's possible that more time passed "in-universe" than 38 seconds, but unlikely that the chase lasted very long, because the Battlecrab was firing on them the entire time and only a single hit was needed.

But if we use your figures, then the Whitestar should have been moving at roughly 50,000 km/s by the time it reached Jupiter, which means it would zip right past Jupiter in 3 seconds. I don't recall the episode in precise detail, but I know it wasn't moving that fast.

[neoolong]

The 38 second figure is derived from timing the scene from the moment the Whitestar breaks combat against the Battlecrab to the moment they plunge into Jupiter.

There are cuts within the scene, but no cuts to any other scene. We saw the Battlecrab fire upon the Whitestar several times, and we are told that a single hit would destroy them. The Battlecrab was also faster than the Whitestar... it was gaining on her.

It's possible that more time passed "in-universe" than 38 seconds, but unlikely that the chase lasted very long, because the Battlecrab was firing on them the entire time and only a single hit was needed.

How do you know there was no time compression? Elliptical editing is usually used in cases like this to shorten the time for an even to something the audience will accept and still understand what is happening.

Is there a clip available of this anywhere?

[[BL]Phalanx]

You could say the same thing about any starship landing on any planet in every sci-fi series, yet it is always understood that some time passes between cuts.

Yes, it's not one continuous shot.

The shortest possible time that the chase lasted is 38 seconds. It could very well have lasted longer. I just don't think it lasted, say, hours...

But if we use your figures, then the Whitestar should have been moving at roughly 50,000 km/s by the time it reached Jupiter, which means it would zip right past Jupiter in 3 seconds. I don't recall the episode in precise detail, but I know it wasn't moving that fast.

One possible explanation is that the Whitestar slowed down before entering Jupiter's atmosphere, but that's unlikely since she was running flat-out for her life and the Battlecrab was still catching up. Slowing down would probably have gotten them killed.

Another is that the Whitestar was slowed drastically from hitting the atmosphere. It's possible, considering that a Whitestar doesn't appear to mass very much. In "Between the Darkness and the Light", impacts from the energy bolts of Thunderbolt-class Starfury fighters are enough to visibly shove Whitestars around a bit. Then again, perhaps slamming into an atmosphere at that speed and slowing down so drastically should've killed the crew anyway, despite that the artificial gravity aboard might compensate, it probably wouldn't compensate quickly enough. We've seen weapon impacts jar the crew, so that system doesn't react instantly.

Or, we can lookat other evidence and revise the calculation. After entering the atmosphere, the Whitestar flew towards the center of Jupiter. Before they reach a depth at which they'll be crushed, the Whitestar turns around and accelerates back out. Timing these scenes would be helpful.

I don't have the tape on hand here, and my own tapes have been lended out, it will have to get timed by somebody else.

[[BL]Phalanx]

How do you know there was no time compression? Elliptical editing is usually used in cases like this to shorten the time for an even to something the audience will accept and still understand what is happening.

Is there a clip available of this anywhere?

I don't know that there was no time compression. I am not asserting that no time compression happened. However, it *is* unlikely that the chase lasted for an hour, for example.

I don't know of any clip of this available online.

[neoolong]

How do you know there was no time compression? Elliptical editing is usually used in cases like this to shorten the time for an even to something the audience will accept and still understand what is happening.

Is there a clip available of this anywhere?

I don't know that there was no time compression. I am not asserting that no time compression happened. However, it *is* unlikely that the chase lasted for an hour, for example.

I don't know of any clip of this available online.

Then you can't say that that is the acceleration. You don't know the time for sure. It may not be as long as an hour, but it doesn't necessarily mean it is 38 seconds. Without knowing the time, the calculation it is pretty much meaningless.

[Mike_6002]

Welcome now I must do this <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*> <*poke*>
that enough

[Darth Wong]

The shortest possible time that the chase lasted is 38 seconds. It could very well have lasted longer. I just don't think it lasted, say, hours...

OK, so the 38-second figure would serve as an upper limit.

One possible explanation is that the Whitestar slowed down before entering Jupiter's atmosphere, but that's unlikely since she was running flat-out for her life and the Battlecrab was still catching up. Slowing down would probably have gotten them killed.

True.

Another is that the Whitestar was slowed drastically from hitting the atmosphere. It's possible, considering that a Whitestar doesn't appear to mass very much. In "Between the Darkness and the Light", impacts from the energy bolts of Thunderbolt-class Starfury fighters are enough to visibly shove Whitestars around a bit. Then again, perhaps slamming into an atmosphere at that speed and slowing down so drastically should've killed the crew anyway, despite that the artificial gravity aboard might compensate, it probably wouldn't compensate quickly enough. We've seen weapon impacts jar the crew, so that system doesn't react instantly.

If the Whitestar entered the atmosphere at 50,000 km/s, it would create a white-hot luminescent shock-front with many times the intensity of the Sun. We did not see this.

Or, we can lookat other evidence and revise the calculation. After entering the atmosphere, the Whitestar flew towards the center of Jupiter. Before they reach a depth at which they'll be crushed, the Whitestar turns around and accelerates back out. Timing these scenes would be helpful.

That would require a usable video clip, preferably in digital format. Perhaps someone can snag it from DVD's when they come out.

I agree that an elapsed time of hours is unrealistic. However, even if the elapsed time is just 10 minutes, the necessary acceleration plummets all the way down to 6 km/s. There's too much variability; I would agree that the Whitestar's acceleration out of Jupiter's atmosphere is a better indicator.

[[BL]Phalanx]

Then you can't say that that is the acceleration. You don't know the time for sure. It may not be as long as an hour, but it doesn't necessarily mean it is 38 seconds. Without knowing the time, the calculation it is pretty much meaningless.

That's why I posted this up to have a discussion about it. That calc can now be revised.

[[BL]Phalanx]

OK, so the 38-second figure would serve as an upper limit.

Yeah, but due to some of the problems pointed out, it probably isn't the correct figure.

If the Whitestar entered the atmosphere at 50,000 km/s, it would create a white-hot luminescent shock-front with many times the intensity of the Sun. We did not see this.

Then that possibility becomes an impossibility...

That would require a usable video clip, preferably in digital format. Perhaps someone can snag it from DVD's when they come out.

Does it necessarily have to come from a DVD? I do have the tapes, just not available to me at this time. I've asked others to see if they can check their tapes and watch the scene to time it for me.

I agree that an elapsed time of hours is unrealistic. However, even if the elapsed time is just 10 minutes, the necessary acceleration plummets all the way down to 6 km/s. There's too much variability; I would agree that the Whitestar's acceleration out of Jupiter's atmosphere is a better indicator.

The Whitestar's flight *into* Jupiter might tell us something, too. However, I don't remember if it's indicated whether they were still accelerating or trying to slow down. IIRC, Whitestar's *are* able to decellerate... they don't necessarily have to turn all the way around and use their main engines. So if it isn't indicated in that scene, the Whitestar may have already been trying to slow down.

[Darth Wong]

Does it necessarily have to come from a DVD? I do have the tapes, just not available to me at this time. I've asked others to see if they can check their tapes and watch the scene to time it for me.

I suppose tapes are acceptable if nothing better is available, but DVD's are obviously better.

The Whitestar's flight *into* Jupiter might tell us something, too. However, I don't remember if it's indicated whether they were still accelerating or trying to slow down. IIRC, Whitestar's *are* able to decellerate... they don't necessarily have to turn all the way around and use their main engines. So if it isn't indicated in that scene, the Whitestar may have already been trying to slow down.

I agree that it must have been trying to slow down, unless the crew is composed of idiots. If you're heading straight down into a gas giant's atmosphere, deceleration seems a rather obvious choice

Besides, the atmosphere probably limited the battlecrab's ability to target the fleeing whitestar, so they could afford to slow down. And the battlecrab's inferior aerodynamics would cause it more difficulty than the whitestar in there.

[neoolong]

Then you can't say that that is the acceleration. You don't know the time for sure. It may not be as long as an hour, but it doesn't necessarily mean it is 38 seconds. Without knowing the time, the calculation it is pretty much meaningless.

That's why I posted this up to have a discussion about it. That calc can now be revised.

Your original post was a conclusion, not an opportunity for discussion. But okay.

[[BL]Phalanx]

Your original post was a conclusion, not an opportunity for discussion. But okay.

Yes, it was a conclusion, but I wanted to start somewhere.

[[BL]Phalanx]

I suppose tapes are acceptable if nothing better is available, but DVD's are obviously better.

We'd all want to use the best source possible, but since we're not analyzing the picture very much and just timing the scene, it shouldn't be too big a deal.

I agree that it must have been trying to slow down, unless the crew is composed of idiots. If you're heading straight down into a gas giant's atmosphere, deceleration seems a rather obvious choice

Besides, the atmosphere probably limited the battlecrab's ability to target the fleeing whitestar, so they could afford to slow down. And the battlecrab's inferior aerodynamics would cause it more difficulty than the whitestar in there.

Actually I'm more wondering about how to figure out how deep the Whitestar went. After searching a few websites about Jupiter, I still haven't found any information about the depths of different parts of Jupiter. At some point, Jupiter becomes liquid metallic hydrogen. The Whitestar didn't go that far. But I've no idea where the gaseous portion ends and the liquid portion begins.

[[BL]Phalanx]

Data on Jupiter at:

http://www.agu.org/sci_soc/young.html

Quoted from the site:

To appreciate the achievement and success of the Galileo probe, one has to know a few facts about the entry into the jovian atmosphere. The probe not only entered at 106,000 mph (about 50 times faster than a high-powered rifle bullet) but also had to enter on a flight path that was 8.5E inclined to the horizontal. An error of 1.51E too shallow and the probe would skip out of the atmosphere; 1.5E too steep and the probe would be destroyed.

Once released from the orbiter 50 million miles from Jupiter, the probe's trajectory could not be altered in any way, nor was any communication possible with the probe until its encounter with Jupiter. Once in the atmosphere, t he probe slowed from 106,000 mph to less than 1000 mph in under 2 min. This deceleration caused the probe to experience 228 times the gravitational acceleration on Earth, or 228 g. A jet fighter pilot experiences the same sort of forces while making a hig h-speed turn, but only about 6 g. During the maximum deceleration, the 750 lb probe "weighed" as much as an empty jumbo jet airplane. Due to the high-speed entry, a shock layer, set up in Jupiter's atmosphere, was located about 1 in from the nose of the p robe. Even though the shock layer's temperature reached 28,000EF (about 2.5 times the Sun's surface temperature), the probe survived because of its protective heat shield.

Can someone explain to me what it means by "8.5E inclined to the horizontal"? How many degrees is that angle?

Anyways, I believe this can be useful for determining how far the Whitestar might've gone into Jupiter at the very least (and maybe also in how far *at the least* that the gas portion goes before it becomes a liquid). Note the part about its initial velocity on entry and the acceleration of the probe and the time for which that acceleration was in effect.

106,000 mph is roughly 47.38 km/sec. (just converting it now so it's easier on me later)

If my math here is correct, we're looking at a distance of roughly ~13,000 kilometers travelled by that probe, assuming "under two minutes" is 90 seconds.

[Crown]

[BL]Phalanx there is an error in your calc's... If it is in orbit around Jupiter, as Gam is it's moon, then you are assuming a straight line of acceleration rather than a more applicable ecliptic orbit.

Second, your equation not only fails to take into it's initial velocity, but the gravitational pull of Jupiter its self.

I understand what you are trying to do, but perhaps if you want, I could look into it for you and see if we may use a classical orbit calc to figure this out. Most likely it would give us a slightly different value. However, given the givens it would still probably be a very high value as well.

I'll try and work it out and get back to you.

PS This is just from the first page, if this has already brought this up, then call me an ass and ignore me, okay?

[[BL]Phalanx]

[BL]Phalanx there is an error in your calc's... If it is in orbit around Jupiter, as Gam is it's moon, then you are assuming a straight line of acceleration rather than a more applicable ecliptic orbit.

Why is that? Why would the Whitestar take an indirect approach when it was running for its life and trying to get to Jupiter as quickly as possible?

Or is it that an ecliptic orbit would actually get it there faster?

Second, your equation not only fails to take into it's initial velocity, but the gravitational pull of Jupiter its self.

Jupiter has roughly 2 and a half times Earth's gravity, right? And the farther away, the less the effect. I figured that neglecting it was no big deal.

The initial velocity of the Whitestar can be assumed to be zero, I think. She was actually heading toward Ganymede initially, then IIRC turned around and flew for Jupiter.

I understand what you are trying to do, but perhaps if you want, I could look into it for you and see if we may use a classical orbit calc to figure this out. Most likely it would give us a slightly different value. However, given the givens it would still probably be a very high value as well.

I'll try and work it out and get back to you.

PS This is just from the first page, if this has already brought this up, then call me an ass and ignore me, okay?

Hey, thanks. Why would I call you an ass for trying to help? LOL...

[Crown]

Hey, thanks. Why would I call you an ass for trying to help? LOL...

Mainly because the difference would be minor, and my point is more of a nitpick. Let me crunch the numbers I'll get back to you tomorrow about it (have to go to work), but I think that it wouldn't be too much different from your figure at all (in fact the more I think about it the more it would actually be the same, consider that if the whitestar had zero absolute velocity at the starting distance, then in order to 'fall' that distance, your equation would hold true, therefore with factoring in a mostly tangential velocity, it wouldn't be different at all!) so in closing let me take a look at it for you, but I have the sinking suspision that I posted irrelevant nit-picks, so until proven otherwise I think that I posted like an ass.

[[BL]Phalanx]

Mainly because the difference would be minor, and my point is more of a nitpick. Let me crunch the numbers I'll get back to you tomorrow about it (have to go to work), but I think that it wouldn't be too much different from your figure at all (in fact the more I think about it the more it would actually be the same, consider that if the whitestar had zero absolute velocity at the starting distance, then in order to 'fall' that distance, your equation would hold true, therefore with factoring in a mostly tangential velocity, it wouldn't be different at all!) so in closing let me take a look at it for you, but I have the sinking suspision that I posted irrelevant nit-picks, so until proven otherwise I think that I posted like an ass.

Your suspicions are groundless. Stop trying to frame yourself, LOL. You didn't come off as an ass to me, anyway. Not like you came in and said "you're an idiot, you didn't account for this and this and this..."

See you later then, whenever you have the spare time.

[Ted C]

I've pointed out in various arguments that if the White Star were capable of the kind of acceleration that people derive by using the minimum 38-second timing, it would also be capable of incredible power generation and have an incredibly dense fuel supply.

If that were the case, Sheridan wouldn't have needed to put two of G'Kar's 500-megaton bombs on board for his planned kamikaze dive into Zha'Ha'Dum, since they would have made in insignificant contribution to the explosion. For instance, if the White Star were capable of over 150,000 G's of acceleration and it had the same mass as a modern Boeing 747, it would need a fuel supply equivalent to over 150 GigaTons of energy. If the fuel alone could release that much energy, the bombs Sheridan put on board would have been pointless.

As noted, the Shadow ship had actually left Ganymede by the time the White Star intercepted it, so we don't actually know how far the ships had to travel to reach Jupiter. We also don't know how much time might have been "edited" from the "documentary footage".

I find that you get reasonable energy estimates (that make those two 500 MT bombs worth something) if you estimate a trip time of 10-15 minutes.

[[BL]Phalanx]

I've pointed out in various arguments that if the White Star were capable of the kind of acceleration that people derive by using the minimum 38-second timing, it would also be capable of incredible power generation and have an incredibly dense fuel supply.

If that were the case, Sheridan wouldn't have needed to put two of G'Kar's 500-megaton bombs on board for his planned kamikaze dive into Zha'Ha'Dum, since they would have made in insignificant contribution to the explosion. For instance, if the White Star were capable of over 150,000 G's of acceleration and it had the same mass as a modern Boeing 747, it would need a fuel supply equivalent to over 150 GigaTons of energy. If the fuel alone could release that much energy, the bombs Sheridan put on board would have been pointless.

Not necessarily. B5 ships' reactors don't explode at a touch. In fact, reactors blowing up is actually a rarity. The reactor on a Whitestar may not even be designed to be able to self-destruct like a bomb going off. Modern nuclear-powered warships aren't able to make their reactors explode like bombs.

And getting destroyed by an impact doesn't seem to do the trick, either. In "No Surrender, No Retreat", we see a Whitestar collide with an Omega, but it doesn't explode violently. Certainly nothing like the way the Trigati was vaporized.

Still, there are other problems with the calc, which I'm trying to revise now. The reason I pointed all this out is that, if I should get another figure using a different instance (Whitestar climbing out of Jupiter), and that figure seems to suggest that the 500 MT nukes at Z'ha'Dum would've been useless, then at least I have this argument.

As noted, the Shadow ship had actually left Ganymede by the time the White Star intercepted it, so we don't actually know how far the ships had to travel to reach Jupiter. We also don't know how much time might have been "edited" from the "documentary footage".

I find that you get reasonable energy estimates (that make those two 500 MT bombs worth something) if you estimate a trip time of 10-15 minutes.

Too much guesswork involved. Anyone can arbitrarily pull a number out and it would be as valid as mine as long as it was greater than 38 seconds and wouldn't involve the Whitestar creating a huge fireball when plunging into Jupiter, or the Whitestar zipping through Jupiter in a few seconds. I remember Gothmog seriously telling me that the chase could've lasted 45 minutes. I found it ridiculous, but what else other than my "gut feelings" do I have to counter a number like that? I don't have anything, and neither does anyone else, and that's the problem. Someone could even conceivably trace the B5 timeline carefully and come up with a figure of hours or maybe even days... and I could talk all I want about them being unreasonable, but there'd be no way I could refute their numbers.

[Connor MacLeod]

Not necessarily. B5 ships' reactors don't explode at a touch. In fact, reactors blowing up is actually a rarity. The reactor on a Whitestar may not even be designed to be able to self-destruct like a bomb going off. Modern nuclear-powered warships aren't able to make their reactors explode like bombs.

1.) Minbari reactors can be set to self destruct. The White Star is at least partially Minbari technology (actually, mostly. ) IF we go by what B5 Wars tells us, it has a reactor system, not a capacitance system like the Vorlon ships use. Perhaps this is an argument in favor of the Minbari's reactors not being typical fusion, I don't know.

2.) They may not be "fragile", but the reactors can explode if damaged - the Omega in War Zone was proof enough - even then, its not relevant if they deliberately set it to do so, or if the fuel supply is particularily reactive (IE antimatter.)

As a side note, we should point out that Ted C's point would also invariably require energy generation involving annihiliation techniques like matter/antimatter to get any sort of reasonable energy generation (I estimate it would take some 1 million kg of reactants to equal Ted's 150 GT estimate.) I estimate A M/AM reaction at say, about 25% efficiency could yield that same amount in about 28-30 tons.

3.) Even if we assume the reactors can't be set off like a bomb, the WS has other ways of inflicting damage - orbital bombardment, kinetic impact through ramming (they dropped the ship from above anyhow - and think about how effective it would have been.) The "kinetic impactor" aspect is perhaps the hardest to deny, and the greatest proof against the acceleration calcs.

And getting destroyed by an impact doesn't seem to do the trick, either. In "No Surrender, No Retreat", we see a Whitestar collide with an Omega, but it doesn't explode violently. Certainly nothing like the way the Trigati was vaporized.

The Trigati deliberately set its reactors to detonate. The two examples are not remotely comparable.

Still, there are other problems with the calc, which I'm trying to revise now. The reason I pointed all this out is that, if I should get another figure using a different instance (Whitestar climbing out of Jupiter), and that figure seems to suggest that the 500 MT nukes at Z'ha'Dum would've been useless, then at least I have this argument.

Ted's points still stand, for the reasons I've mentioned. Regardless of the method of destruction, it still points to the fact that the WS could not generate any more than a 1000 megatons of power at any given instant.

Too much guesswork involved. Anyone can arbitrarily pull a number out and it would be as valid as mine as long as it was greater than 38 seconds and wouldn't involve the Whitestar creating a huge fireball when plunging into Jupiter, or the Whitestar zipping through Jupiter in a few seconds. I remember Gothmog seriously telling me that the chase could've lasted 45 minutes. I found it ridiculous, but what else other than my "gut feelings" do I have to counter a number like that? I don't have anything, and neither does anyone else, and that's the problem. Someone could even conceivably trace the B5 timeline carefully and come up with a figure of hours or maybe even days... and I could talk all I want about them being unreasonable, but there'd be no way I could refute their numbers.

Err, wait. You're refuting the guesswork in Ted's calcs? Isn't the same true of the so called "production rate" calcs for the "Xha'Dam" base in "Armies of Light and Dark?" There is certainly alot of ambiguity THERE as to the timeframe, as I've repeatedly TOLD Fivers in the past. One can derive a POSSIBLE estimate based on the assumptions usually made, and they CAN be interpreted in that fashion, but they are by no means concrete estimates.

Even moreso, its ridiculous to assume that the Shadows can build massive planetkillersr in mere minutes or hours if it takes them months or even years to build the smallest class of shadow cruiser (the patrol cruiser from "Wars of the Ancients" is specifically stated to take a "few months or even few years" to grow, which is for those ships a "short production cycle.") Or beyond that, why would Primordials take centuries to grow to their full measure (rather than being artificially grown as Ancient vessels are) if said PKs (which are VASTLY more powerful) take minutes or hours?

It seems that if there are some Fivers are willing to SOME calcs on Guesswork, then Ted C is perfectly justified in doing so as well.

[Connor MacLeod]

My question is, if we assume that the WS WAS to be rammed into the planet in the observable timeframe, could we not generate acceleration calcs for this?

As I said before, the WS could not have generated more than a GT worth of kinetic energy, else the nukes would have been superfluous. If we know the time and estimate the mass (which we can do) for the WS, one can probably generate an upper-limit on acceleration for that instance.